Picture display devices in the form of cubes and other polyhedrons have been the subject of inventive activity in the past. Representative samples of prior art patents include the following.
U.S. Pat. No. 470,222 to Townsend discloses a paper weight comprising a transparent slab that rests within a recess formed in a frame. Pictures can be displayed by placing them between the slab and frame. The frame includes a pair of springs that are biased against small recesses formed in the slab. Such springs are intended to prevent relative lateral movement between the slab and the frame. However, it is clear from the disclosure of Townsend that gravity, not the springs provides the primary means by which the slab remains seated in the frame. Thus, the slab would easily separate from the frame and come crashing to the floor if the paper weight was rotated 90 degrees, or inverted.
U.S. Pat. No. 2,572,454 to Down et al. discloses a transparent cube with a shallow, blind recess formed in each face, a photograph fit into each of the blind recesses, and a transparent plug pressed into and closing each recess. The cube is then rotatably supported at opposite corners on a display stand. Once a selection of pictures has been made and sealed in the cube, the pictures cannot thereafter be replaced.
U.S. Pat. No. 3,364,603 to Tate, Jr. discloses a nameplate having an “advertising field” on the back of the nameplate. The advertising field includes a prism that slides or snaps into an extruded frame so that a calendar, advertising material, etc. can be sandwiched between the prism and frame, and therefore viewed from the rear of the nameplate. Tate, Jr.'s nameplate is designed for stationary use; tilting either end of the nameplate upwardly would cause the prism to slide out the opposite end of the frame.
U.S. Pat. No. 3,561,146 to Dembar shows a pictorial display apparatus in the form of a cube, a hexagon, or a truncated prism. The apparatus comprises a thin, transparent body having a plurality of sides defining a hollow interior which is filled with a resilient foam material of a shape that conforms to the shape of the hollow interior. A photo is placed behind each of the thin transparent sides and held in place by the resilient material. An opaque backing is located behind the photos as a backdrop. Dembar's display apparatus is thus constructed of many elements, each of which are relatively expensive to manufacture, and labor intensive to assemble.
U.S. Pat. No. 3,658,413 to Cornell discloses two embodiments of display devices. The first comprises a base, a support rotatably mounted on the base, and a transparent polyhedron resting on the support. The support has three square, planar surfaces joined along three contiguous edges to form an open, tri-faceted cavity sharing a common corner. A pin depends symmetrically relative to the planar surfaces from the common corner and is rotatably received within a mating cylindrical recess in the base permitting the support to rotate relative to the base. A picture or other planar object is supported on each of the surfaces of the cavity. A transparent cube is laid in the cavity with one corner of the cube fitting within the common corner. The pictures are viewed through the cube by looking through the surface of the cube which is opposite and parallel to the surface on which the photo is supported. The display device has a plurality of parts which fit together but are held in vertical alignment by gravitational forces. The display is not self-contained and cannot be easily moved or handled. An accidental blow thereto could send all parts flying in different directions. In the other embodiment, a 14-sided polyhedron includes an array of square and triangular surfaces formed on a transparent block. The patent is not clear as to whether the polyhedron is intended to rest in a similarly shaped, multi-faceted cavity, as in the first embodiment, or whether each photo is to be attached to a supporting surface to be seen through an opposite, viewing surface. If the former, the embodiment is subject to the same deficiencies as the first embodiment. If the latter, the photos are apparently secured to their respective surfaces by adhesives or the like, which exposes the photos to deterioration and/or destruction from direct contact with the outside world.
U.S. Pat. No. 3,703,045 to Nyman shows a pair of hollow shells in the shape of cubes, one of which fits contiguously within the other. At least the outer shell is transparent and has a removable, sliding side which allows access to its interior. Planar spaces are provided between the cubes for pictures. The structure is costly to make and appears to be relatively fragile in use.
As the foregoing suggests, one primary deficiency of the pictorial displays of prior art is that they are unstable when moved from a stationary, horizontal display surface.